display coeff of transfer function and a graph in frequency domain for realliZation

- as user adds poles/zeros gui should update a list of coefficients for trans function. - there must be a button to display the transfer function freq domain, may be use fiview to display this plot

Effects GUI and LADSPA for Mixxx

Building upon Effects framework (mixxx/+spec/effects-1.0) make complete GUI and incorporate LADSPA for effect plugins. See whiteboard below for status and upcoming stuff.